GRB231118A

Analysis Summary

Notes:

1) No attempt has been made to eliminate the non-significant decimal places.
2) This batgrbproduct analysis is done using the HEASARC data.
3) This batgrbproduct analysis is using the flight position for the mask-weighting calculation.

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.48
    Process Start Time: Tue Dec 26 15:35:50 EST 2023
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1197311
======================================================================

  Trigger: 01197311      Segment: 000

  BAT Trigger Time: 722020625.6   [s; MET]
      Trigger Stop: 722020626.624   [s; MET]
               UTC: 2023-11-18T17:16:33.206740    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 4.84300825958335   Dec: -48.0355229992106  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    20.93
     Image Trigger?:     NO
     Rate S/N Ratio:     109.261155036911  [ if not an image trigger ]
     Image S/N Ratio:    20.93

  Analysis Position:   [ source = BAT ]
    RA: 4.84300825958335   Dec: -48.0355229992106  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 4.84002144555348   Dec: -48.0435836136321  [deg; J2000]  
        { 00h 19m 21.6s , -48d 02' 36.9" }
         +/- 0.771656755759291 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.276696807313094 [arcmin] (formal 1-sigma fit error)
    SNR: 44.0495021802502
 
  Angular difference between the analysis and refined position is 0.498259 arcmin
 
  Partial Coding Fraction: 0.5546875    [ including projection effects ]

  Duration
     T90: 151.488000035286 +/- 94.0267835021085
        Measured from: -4.28799998760223
                   to: 147.200000047684     [s; relative to TRIGTIME]
     T50: 6.94400000572205 +/- 7.22240067068257
        Measured from: -1.27999997138977
                   to: 5.66400003433228     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.0759999752044678     
                   to: 0.924000024795532     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -6.84800004959106     
                   to: 250.447999954224     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.479493   2.282292   1.915264   0.661529
           0.107738   0.112908   0.098957   0.084262 [error]
 Peak      0.228087   0.405804   0.420003   0.143980
           0.014191   0.017673   0.017622   0.013066 [error]

     [ fluence units of on-axis counts / fully illuminated detector ] 

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  257.296   -6.848  250.448
T90   151.488   -4.288  147.200
T50     6.944   -1.280    5.664
Peak    1.000   -0.076    0.924
 
 
====== Spectral Analysis Summary =====================================
 
Model      : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index   : photon index: E^{Ph_index}
Ph_90err   : 90% error of the photon index
Epeak      : Epeak in keV
Epeak_90err: 90% error of Epeak
Norm       : normalization at 50 keV in both the PL model and CPL model
Nomr_90err : 90% error of the normalization
chi2       : Chi-Squared
dof        : degree of freedo
 
=== Time-averaged spectral analysis ===
(Best model with acceptable fit: PL)
 
Model Ph_index Ph_90err_low Ph_90err_hi  Epeak  Epeak_90err_low  Epeak_90err_hi  Norm       Nomr_90err_low    Norm_90err_hi    chi2    dof
PL      -1.387    -0.097      0.097       -           -               -         1.68e-03     -8.94e-05          8.94e-05      55.720   57
CPL     -1.373    -0.111      0.330     9930.270    -9930.270      -9930.270      1.70e-03     -1.09e-04          6.95e-04      55.870   56
 
 
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: N/A)
 
Model Ph_index Ph_90err_low Ph_90err_hi  Epeak  Epeak_90err_low  Epeak_90err_hi  Norm       Nomr_90err_low    Norm_90err_hi    chi2    dof
PL      -1.143     -0.078     0.078       -           -               -         8.25e-02     -3.80e-03          3.80e-03      55.800   57
CPL     -0.606     -0.330     0.357      145.042     -36.884       134.505      1.46e-01     -4.20e-02          6.45e-02      47.750   56
 
 
=== Fluence/Peak Flux Summary ===
 
              Model    Band1     Band2     Band3     Band4     Band5     Total
                       15-25     25-50    50-100    100-350    15-150    15-350    keV
Fluence         PL   4.96e-07  9.76e-07  1.49e-06  4.98e-06  4.18e-06  7.95e-06   erg/cm2
      90%_error_low -4.98e-08 -5.88e-08 -9.89e-08 -7.03e-07 -2.43e-07 -7.70e-07   erg/cm2
      90%_error_hi   5.14e-08  5.84e-08  9.84e-08  7.81e-07  2.44e-07  8.33e-07   erg/cm2
Peak flux       PL   6.12e-04  9.28e-03  1.07e-01  9.38e+00  4.73e-01  9.40e+00   ph/cm2/s
      90%_error_low     N/A       N/A       N/A       N/A       N/A       N/A     ph/cm2/s
      90%_error_hi      N/A       N/A       N/A       N/A       N/A       N/A     ph/cm2/s
 
Fluence        CPL   4.98e-07  9.74e-07  1.49e-06  5.01e-06  4.19e-06  7.69e-06   erg/cm2
      90%_error_low -6.40e-08 -5.90e-08 -1.00e-07 -2.06e-06 -2.73e-07 -1.67e-06   erg/cm2
      90%_error_hi   5.31e-08  6.38e-08  1.14e-07  7.85e-07  2.02e-07  1.05e-06   erg/cm2
Peak flux      CPL   2.12e+00  3.11e+00  2.90e+00  2.57e+00  9.42e+00  1.07e+01   ph/cm2/s
      90%_error_low -2.67e-01 -1.83e-01 -1.77e-01 -6.52e-01 -4.71e-01 -8.15e-01   ph/cm2/s
      90%_error_hi   2.75e-01  1.85e-01  1.79e-01  9.24e-01  4.71e-01  1.01e+00   ph/cm2/s
 
======================================================================

Special notes of this burst

Image

Pre-slew 15.0-350.0 keV image (Event data)

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
    4.8400   -48.0436   0.0044    33.6517  -134.2177         4.8647375     44.050 TRIG_01197311                 
 
Foreground time interval of the image:
 -6.848  12.701 (delta_t =  19.549 [sec])
Background time interval of the image:
-239.600  -6.848 (delta_t = 232.752 [sec])

Light Curves

Note: The mask-weighted lightcurves have units of either count/det or counts/sec/det, where a det is 0.4 x 0.4 = 0.16 sq cm.

Full-time range; 1 s binning

Bokeh Plot

Other quick-look light curves:

64 ms binning (zoomed)
16 ms binning (zoomed)
8 ms binning (zoomed)
2 ms binning (zoomed)
SN=5 or 10 s binning (full-time range)
Raw light curve

Spectra

Notes:

1) The fitting includes the systematic errors.
2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.

Time averaged spectrum fit using the average DRM

Power-law model

Time interval is from   -6.848 sec. to  250.448 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.38705     ( -0.0967608   0.0971427 )
Norm@50keV  : 1.67784E-03    ( -8.93955e-05   8.93589e-05 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   55.72     using 59 bins.
 Reduced chi-squared = 0.977544
# Null hypothesis probability of 5.23e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 257.3 sec: 0.203741 ( -0.011428  0.011461 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.18311e-06 ( -2.42711e-07  2.43795e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   -6.848 sec. to  250.448 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.3732     ( -0.099298   0.341149 )
Epeak [keV] : 9930.27      ( -9999.36 -9999.36 )
Norm@50keV  : 1.70310E-03    ( -8.96053e-05   0.000714042 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   55.87     using 59 bins.
 Reduced chi-squared = 0.997679
# Null hypothesis probability of 4.80e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 257.3 sec: 0.203997 ( -0.012474  0.011665 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.18967e-06 ( -2.72702e-07  2.02307e-07 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from   -0.076 sec. to    0.924 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.14325     ( -0.0780846   0.0784511 )
Norm@50keV  : 8.25499E-02    ( -0.00379928   0.00379875 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   55.80     using 59 bins.
 Reduced chi-squared = 0.978947
# Null hypothesis probability of 5.20e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 0.473115 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.51628e-07 ( -4.30722e-08  4.32009e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from   -0.076 sec. to    0.924 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.606252     ( -0.330102   0.357336 )
Epeak [keV] : 145.042      ( -36.884 134.506 )
Norm@50keV  : 0.145644    ( -0.0420186   0.0644659 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   47.75     using 59 bins.
 Reduced chi-squared = 0.852679
# Null hypothesis probability of 7.76e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 9.42416 ( -0.47077  0.47071 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.90766e-07 ( -2.88387e-08  2.40467e-08 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 151.488 sec.
Hardness ratio (energy fluence ratio) = 1.52943119797

S(15-50 keV) vs. S(50-150 keV) plot

S(15-50 keV)  = 1.4724124e-06
S(50-150 keV) = 2.710759e-06

The dash-dotted line and the dashed line traces the fluences calculated from the Band function with Epeak = 15 and 150 keV, respectively. Both lines assume a canonical values of alpha = -1 and beta = -2.5.

Mask shadow pattern

IMX = -4.642506576847473E-01, IMY = 4.771047898462376E-01

Spacecraft aspect plot

Bright source in the pre-burst/pre-slew/post-slew images

Pre-burst image of 15-350 keV band

Time interval of the image:
-239.600000 -6.848000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 52.6470 -30.1047    2.9  45.7  162.8   3.3520   4.1 ------	UNKNOWN                       
312.7461   2.2456    2.2  55.2  -32.3   9.2798   5.3 ------	UNKNOWN

Pre-slew background subtracted image of 15-350 keV band

Time interval of the image:
-6.848000 12.700590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
334.8134  30.1612    2.3  53.7   10.9   1.9574   5.0 ------	UNKNOWN                       
 60.7956 -46.0940    2.9  55.6 -178.9   1.2162   4.0 ------	UNKNOWN                       
326.8634  14.1058    2.8  48.0  -10.7   0.6643   4.0 ------	UNKNOWN                       
 60.2243 -56.8071    2.2  58.9 -166.8   2.7479   5.3 ------	UNKNOWN                       
315.7638  16.8041    2.1  58.5  -15.0   2.6172   5.5 ------	UNKNOWN                       
  4.8400 -48.0436    0.3  33.7 -134.2   4.8643  44.0 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
83.500600 962.531700
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 76.2666 -48.5982    3.3  45.7  162.8  10.6251   3.5 ------	UNKNOWN                       
113.9720 -68.9348    3.5  52.0 -161.5   9.9853   3.3 ------	UNKNOWN

Analysis Summary

Notes:

Image

Pre-slew 15.0-350.0 keV image (Event data)

Light Curves

Full-time range; 1 s binning

Other quick-look light curves:

64 ms binning (zoomed) 16 ms binning (zoomed) 8 ms binning (zoomed) 2 ms binning (zoomed) SN=5 or 10 s binning (full-time range) Raw light curve

Spectra

Notes:

Time averaged spectrum fit using the average DRM

Power-law model

Cutoff power-law model

1-s peak spectrum fit

Power-law model

Cutoff power-law model

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

S(15-50 keV) vs. S(50-150 keV) plot

Mask shadow pattern

Spacecraft aspect plot

Bright source in the pre-burst/pre-slew/post-slew images

Pre-burst image of 15-350 keV band

Pre-slew background subtracted image of 15-350 keV band

Post-slew image of 15-350 keV band

64 ms binning (zoomed)
16 ms binning (zoomed)
8 ms binning (zoomed)
2 ms binning (zoomed)
SN=5 or 10 s binning (full-time range)
Raw light curve